Solid-state imaging element and electronic

ABSTRACT

The present disclosure relates to a solid-state imaging element and electronic equipment that make it possible to sufficiently secure a time width of a pulse signal. In an AD converter for each unit pixel, a pulse generation circuit feeds back a delay signal obtained by delaying an output signal of the comparator to the comparator and arithmetically operates the output signal and the delay signal to generate a pulse signal. A latch circuit latches the pulse signal generated by the pulse generation circuit. The present disclosure can be applied to a solid-state imaging element of a stacked type and a back side illumination type.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International PatentApplication No. PCT/JP2017/047265 filed on Dec. 28, 2017, which claimspriority benefit of Japanese Patent Application No. JP 2017-004081 filedin the Japan Patent Office on Jan. 13, 2017. Each of theabove-referenced applications is hereby incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present disclosure relates to a solid-state imaging element andelectronic equipment, and particularly relates to a solid-state imagingelement and electronic equipment that make it possible to sufficientlysecure a time width of a pulse signal.

BACKGROUND ART

A system has been proposed in which, in order to allow an imagingelement, in which pixels are disposed two-dimensionally, to deal withspeeding up of image signal outputting, an analog to digital conversiondevice is disposed in each pixel such that analog to digital conversionis performed simultaneously by all pixels to speed up analog to digitalconversion. In this system, a comparison section compares an analogimage signal and a reference signal with each other. Then, when thevoltage of the reference signal transits from a state in which it islower than the voltage of the analog image signal to a state in which itis higher than the voltage of the analog image signal or from a state inwhich it is higher the voltage of the analog image signal to a state inwhich it is lower the voltage of the analog image signal, this voltagechange is detected and outputted as a comparison result. Further, adigital code corresponding to the voltage of the reference signal isinputted to a latch circuit, and the inputted digital code is retainedby the latch circuit on the basis of the detection result by thecomparison circuit. Thereafter, the digital code retained in the latchcircuit is outputted as the result of the analog to digital conversion.

The imaging device in PTL 1 is configured such that it has a functionfor feeding back an output signal of the comparator into the comparatorin order to accelerate the signal transition in the comparator. Then, aneffective Window is provided using the signal, and the start and the endof a data validity period of the latch circuit is adjusted.

CITATION LIST Patent Literature

[PTL 1]

WO 2016/136448

SUMMARY Technical Problem

However, in order to secure such a pulse width sufficient to allow asignal from a repeater to be acquired, it is necessary to increase acircuit area.

The present disclosure has been made in view of such a situation asdescribed above and makes it possible to sufficiently secure a timewidth of a pulse signal.

Solution to Problem

A solid-state imaging element according to one aspect of the presenttechnology includes a pixel array section in which unit pixels eachhaving a photoelectric conversion section are disposed, and an ADconverter for each of the unit pixels, in which the AD converterincludes a pulse generation circuit that feeds back a delay signalobtained by delaying an output signal of a comparator to the comparatorand performs arithmetic operation of the output signal and the delaysignal to generate a pulse signal, and a latch circuit that latches adata code using the pulse signal generated by the pulse generationcircuit.

The pulse generation circuit may include a delay element that delays theoutput signal of the comparator to generate the delay signal, and anarithmetic element that arithmetically operates the output signal andthe delay signal to generate the pulse signal.

The arithmetic element includes a NOR circuit.

The arithmetic element includes a NAND circuit.

In the pulse generation circuit, a logical threshold value of a gateelement is adjusted.

In the pulse generation circuit, the logical threshold value of the gateelement is adjusted by changing an element number of transistors.

In the pulse generation circuit, the logical threshold value of the gateelement is adjusted by setting the threshold value of each of theelements of transistors to a high threshold value and a low thresholdvalue.

The pulse generation circuit may further include a selection circuitthat selects a path used when a delay signal obtained by delaying theoutput signal of the comparator is to be fed back to the comparator andthe output signal and the delay signal are arithmetically operated togenerate a pulse signal and another path used when the output signal ofthe comparator is to be used as it is.

Electronic equipment according to the one aspect of the presenttechnology includes: a solid-state imaging element including a pixelarray section in which unit pixels each having a photoelectricconversion section are disposed, and an AD converter for each of theunit pixels, in which the AD converter includes a pulse generationcircuit that feeds back a delay signal obtained by delaying an outputsignal of a comparator to the comparator and performs arithmeticoperation of the output signal and the delay signal to generate a pulsesignal, and a latch circuit that latches a data code using the pulsesignal generated by the pulse generation circuit; a signal processingcircuit that processes an output signal outputted from the solid-stateimaging element; and an optical system that enters incident light intothe solid-state imaging element.

In the one aspect of the present technology, a delay signal formed bydelaying an output signal of the comparator by the AD converter of eachof the unit pixels, which are disposed in the pixel array section andeach include the photoelectric conversion section, is fed back to thecomparator, and the output signal and the delay signal arearithmetically operated to generate a pulse signal. Then, a data code islatched using the generated pulse signal.

Advantageous Effects of Invention

With the present technology, a time width of a pulse signal can besecured sufficiently.

It is to be noted that the advantageous effects described in the presentspecification are merely examples, and the advantageous effects of thepresent technology are not restricted to the advantageous effectsdescribed in the present specification and there may be additionaladvantageous effects.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram depicting a general configuration example of asolid-state imaging element to which the present technology is applied.

FIG. 2 is a block diagram depicting a configuration example of part ofthe solid-state imaging element to which the present technology isapplied.

FIG. 3 is a view depicting a configuration example of an AD conversiondevice.

FIG. 4 is a view depicting another configuration example of the ADconversion device.

FIG. 5 is a view depicting a configuration example of an AD conversiondevice to which the present technology is applied.

FIG. 6 is a circuit diagram depicting a configuration example of a pulsegeneration circuit.

FIG. 7 is a circuit diagram depicting a configuration example of part ofa solid-state imaging element to which the present technology isapplied.

FIG. 8 is a circuit diagram depicting another configuration example ofpart of the solid-state imaging element to which the present technologyis applied.

FIG. 9 is a circuit diagram depicting a different configuration exampleof the pulse generation circuit of FIG. 6.

FIG. 10 is a circuit diagram depicting another different configurationexample of the pulse generation circuit of FIG. 6.

FIG. 11 is a circuit diagram depicting a configuration example of thepulse generation circuit of FIG. 6 in the case where a NAND circuit isused as an arithmetic element.

FIG. 12 is a circuit diagram depicting a configuration example of thepulse generation circuit of FIG. 9 in the case where a NAND circuit isused as an arithmetic element.

FIG. 13 is a circuit diagram depicting a configuration example of thepulse generation circuit of FIG. 10 in the case where a NAND circuit isused as an arithmetic element.

FIG. 14 is a circuit diagram depicting a configuration example of thepulse generation circuit of FIG. 6 in the case where a selector circuitis inserted.

FIG. 15 is a block diagram depicting a configuration example of an ADconversion device to which the present technology is applied.

FIG. 16 is a process chart of a fabrication process of a solid-stateimaging element.

FIG. 17 is a view depicting an example of use of an image sensor towhich the present technology is applied.

FIG. 18 is a block diagram depicting a configuration example ofelectronic equipment to which the present technology is applied.

FIG. 19 is a block diagram depicting an example of a schematicconfiguration of an in-vivo information acquisition system.

FIG. 20 is a view depicting an example of a schematic configuration ofan endoscopic surgery system.

FIG. 21 is a block diagram depicting an example of a functionalconfiguration of a camera head and a camera control unit (CCU).

FIG. 22 is a block diagram depicting an example of schematicconfiguration of a vehicle control system.

FIG. 23 is a diagram of assistance in explaining an example ofinstallation positions of an outside-vehicle information detectingsection and an imaging section.

DESCRIPTION OF EMBODIMENT

In the following, a mode for carrying out the present disclosure(hereinafter referred to as an embodiment) is described. It is to benoted that the description is given in the following order.

0. Description of Device

1. Embodiment

2. Example of Use of Image Sensor

3. Example of Electronic Equipment

4. Application Example to In-Vivo Information Acquisition System

5. Application Example to Endoscopic Surgery System

6. Application Example to Moving Body

0. Description of Device

<Schematic Configuration Example of Solid-State Imaging Device>

FIG. 1 depicts a schematic configuration example of one example of aCMOS (Complementary Metal Oxide Semiconductor) solid-state imagingelement applied to embodiments of the present technology.

As depicted in FIG. 1, a solid-state imaging element (element chip) 1includes a pixel region (so-called imaging region) 3 in which aplurality of pixels 2 each including a photoelectric conversion elementis arrayed regularly and two-dimensionally on a semiconductor substrate11 (for example, a silicon substrate), and a peripheral circuit region.

Each pixel 2 includes a photoelectric conversion element (for example, aPD (Photo Diode)) and a plurality of pixel transistors (so-called MOStransistors). The plurality of pixel transistors can include, forexample, three transistors of a transfer transistor, a reset transistor,and an amplification transistor. Also, the plurality of pixeltransistors can include four transistors, further adding a selectiontransistor to the three transistors above.

Also it is possible for the pixels 2 to have a shared pixel structure.The shared pixel structure includes a plurality of photodiodes, aplurality of transfer transistors, a single shared floating diffusion,and other pixel transistors shared one by one. The photodiodes arephotoelectric conversion elements.

The peripheral circuit region includes a vertical driving circuit 4, acolumn signal processing circuit 5, a horizontal driving circuit 6, anoutputting circuit 7, and a control circuit 8.

The control circuit 8 receives an input clock and data that instructs anoperation mode and so forth and outputs data of internal information andso forth of the solid-state imaging element 1. In particular, thecontrol circuit 8 generates a clock signal that becomes a reference tooperation of the vertical driving circuit 4, the column signalprocessing circuit 5, and the horizontal driving circuit 6, and acontrol signal on the basis of a vertical synchronizing signal, ahorizontal synchronizing signal and a master clock. Then, the controlcircuit 8 inputs the signals to the vertical driving circuit 4, thecolumn signal processing circuit 5, and the horizontal driving circuit6.

The vertical driving circuit 4 is configured, for example, from a shiftregister, and selects a pixel driving wiring line and supplies a pulsefor driving a pixel 2 to the selected pixel driving line to drive pixels2 in units of rows. In particular, the vertical driving circuit 4selectively scans the pixels 2 of the pixel array 3 in units of rowssuccessively in a vertical direction and supplies a pixel signal basedon a signal charge generated in response to a received light amount, forexample, at the photoelectric conversion element of each of the pixels 2through a vertical signal line 9 to the column signal processing circuit5.

The column signal processing circuit 5 is disposed, for example, foreach column of the pixels 2 and performs signal processing of signalsoutputted from the pixels 2 for one row such as noise removal for eachpixel column. In particular, the column signal processing circuit 5performs signal processing such as CDS (Correlated Double Sampling) forremoving fixed pattern noise unique to the pixels 2, signalamplification, A/D (Analog/Digital) conversion, and so forth. Ahorizontal selection switch (not depicted) is provided in the outputstage of the column signal processing circuit 5 such that it isconnected between the column signal processing circuit 5 and ahorizontal signal line 10. It is to be noted that part of the signalprocessing described above may be processed for each pixel.

The horizontal driving circuit 6 is configured, for example, from ashift register, and sequentially outputs a horizontal scanning pulse toselect each of the column signal processing circuits 5, and then, apixel signal is outputted from each of the column signal processingcircuits 5 to the horizontal signal line 10.

The outputting circuit 7 performs signal processing for each of signalssuccessively supplied from the column signal processing circuits 5through the horizontal signal line 10 and outputs a resulting signal.For example, the outputting circuit 7 sometimes performs only bufferingor sometimes performs black level adjustment, column dispersioncorrection, various digital signal processes and so forth.

Input/output terminals 12 are provided to transfer a signal to and fromthe outside.

1. Embodiment <Structure Example of Solid-State Imaging Element>

FIG. 2 is a block diagram depicting a configuration example of part of asolid-state imaging element to which the present technology is applied.The present technology is applied to a solid-state imaging element notof the example that includes an AD conversion device for each column asdepicted in FIG. 1 but of an example in which an AD (Analog-Digital)conversion device 61 is provided for each pixel 2.

In the example of FIG. 2, a pixel 2 and an AD conversion device 61 thatreceives a pixel signal from the pixel 2 and a reference signal from acontrol circuit 8 as inputs thereto and converts them into digitalsignals as well as a repeater 31, a RAM CDS 32 and a Gray Code 33 thatare disposed for each predetermined pixel column in the subsequent stageto the AD conversion device 61 are depicted. It is to be noted that theAD conversion device 61 is configured particularly from an AD converter51 and a latch circuit 26.

The AD conversion device 61 includes a comparison circuit 22, an autozero (AZ) 23, a PFB (Possitive Feed Back) 24, a pulse generation circuit25, and a latch circuit 26. The comparison circuit 22 receives a pixelsignal and a reference signal as inputs thereto and outputs a result ofcomparison of them to the PFB 24. The auto zero 23 has a function forresetting the comparison circuit 22. The PFB 24 is a speeding upcircuit, and receives an inversion signal from the comparison circuit 22and a feedback (Feed Back) signal from the pulse generation circuit 25as inputs thereto and outputs a comparison signal to the pulsegeneration circuit 25 of the subsequent stage.

The pulse generation circuit 25 includes a delay element 41, anarithmetic element 42, and an inversion element 43. The pulse generationcircuit 25 performs delay arithmetic operation for providing aneffective Window for acquiring data and receives the inversion signaland a delay signal obtained by delaying the inversion signal as inputsthereto to generate a pulse signal (VCO PULSE). Then, the pulsegeneration circuit 25 outputs the generated pulse signal to the latchcircuit 26, and inverts the delay signal and feeds back the inverteddelay signal as a feedback signal to the PFB 24. The latch circuit 26stores a data code using the pulse signal for a predetermined period oftime and outputs the stored data code to the repeater 31.

In particular, in PTL 1, the AD conversion device 61 is configured suchthat a comparison signal from a comparator 40 is fed back as a feedbacksignal to the comparison circuit 22 as depicted in FIG. 3. It is to benoted that the comparator 40 includes the comparison circuit 22 and thePFB 24. Meanwhile, although the AD conversion device 61 of the exampleof FIG. 4 it includes the delay element 41 and the arithmetic element42, even if the delay element 41 is provided, a comparison signal fromthe comparator 40 is fed back to the comparator 40 in front of the delayelement 41.

On the other hand, in the AD conversion device 61 to which the presenttechnology is applied, a delay signal after delay arithmetic operationis completed through the delay element 41 is used as a feedback signalthat is fed back to the comparator 40.

Consequently, a feedback function for accelerating inversion transitionof an output of the comparator 40 and a pulse generation functionsufficient to acquire a signal from the repeater 31 using a delay signalare both achieved.

FIG. 6 is a circuit diagram depicting a configuration example of a pulsegeneration circuit.

The pulse generation circuit 25 of FIG. 6 receives an inverted output(VCO) of the comparison circuit 22 (comparator 40) as an input signalthereto and generates a delay signal using the delay element 41 that isan inverter. Further, the pulse generation circuit 25 receives the delaysignal and the inverted output of the comparator 40 to an arithmeticelement 42 that is a NOR circuit as inputs thereto and generates a pulsesignal (VCO PULSE). Then, as a feedback signal (PFB) for acceleratingsignal transition of the second stage of the comparison circuit 22, adelay signal inverted by the inversion element 43 that is an inverter isused. In particular, in the example of FIG. 6, the delay element 41 andthe inversion element 43 each include an inverter, and the arithmeticelement 42 includes a NOR circuit.

FIG. 7 is a circuit diagram depicting a configuration example of part ofa solid-state imaging element to which the present technology isapplied. It is to be noted that, in the case of the example of FIG. 7,an example of a pixel 2 that includes one PD for one FD is illustrated.

In the example of FIG. 7, as part of the solid-state imaging element 1,a pixel 2 including FD, PD, TX and OFG, a comparison circuit 22including a differential pair of nMOS and pMOS, an AZ 23, a PFB 24including 2ND and a NOR circuit, and inverters 71 and 72 interposedbetween the PFB 24 and a latch circuit 26.

In this circuit configuration, nMOS of the differential pair of thecomparison circuit 22 (in the circuit of FIG. 7, an input differentialpair) is an upper chip 81, and elements following nMOS are a lower chip.The upper and lower chips are connected to each other at totaling twoplaces including each one node of the differential pair of thecomparison circuit 22.

It is to be noted that the connection places of the upper and lowerchips are not limited to those of the circuit of FIG. 7 but aredetermined from various factors such as area restriction or circuitcharacteristics.

FIG. 8 is a circuit diagram depicting a different configuration exampleof part of the solid-state imaging element to which the presenttechnology is applied. It is to be noted that, although the circuitconfiguration of FIG. 8 is different from that of FIG. 7 in that it hasa pixel sharing configuration including four PDs for one FD, theconfiguration of the other part of FIG. 8 is common to the circuitconfiguration of FIG. 7. In other words, the present technology can beapplied also to a pixel sharing configuration.

It is to be noted that the circuit configuration is not limited to anyof the circuits depicted in FIGS. 7 and 8 but can be applied to a pixelAD type solid-state imaging element of any other configuration. Forexample, in a solid-state imaging element of the pixel AD type of adifferent configuration, the comparison circuit 22 including pMOS of adifferential pair is adopted and, in addition, an FD is made not acomponent of the comparison circuit 22 but is connected through a sourcefollower circuit. In this case, connection between the upper and lowerchips is performed only at one place of the comparator and the inputnode of the terminal.

FIG. 9 is a circuit diagram depicting a different configuration exampleof the pulse generation circuit of FIG. 6.

In the pulse generation circuit 25 of FIG. 9, the element number oftransistors configuring the pulse generation circuit 25 of FIG. 6 ischanged to adjust the logical threshold value of the transistors. Inparticular, the pulse generation circuit 25 of FIG. 9 receives aninverted output (VCO) of the comparison circuit 22 as an input theretoand generates a delay signal using the delay element 41 that is aninverter having low logic.

Further, in the pulse generation circuit 25, the delay signal and theinverted output of the comparison circuit 22 are inputted to thearithmetic element 42 that is a NOR circuit having a high logicalthreshold value to generate a pulse signal (VCO PULSE). Then, as thefeedback signal (PFB) for accelerating signal transition in the secondstage of the comparison circuit 22, a delay signal inverted by theinversion element 43 that is an inverter is used.

FIG. 10 is a circuit diagram depicting a further configuration exampleof the pulse generation circuit of FIG. 6.

In the pulse generation circuit 25 of FIG. 10, the elements of thetransistors configuring the pulse generation circuit 25 of FIG. 6 arechanged to those having different threshold values (HVT: High Vth Tr.and LVT: Low Vth Tr.) to adjust the logical threshold value of each ofthe transistors. In particular, the pulse generation circuit 25 of FIG.10 receives an inverted output (VCO) of the comparison circuit 22 as aninput thereto and generates a delay signal using the delay element 41that is an inverter having low logic.

Further, the pulse generation circuit 25 inputs the delay signal and theinverted output of the comparison circuit 22 to the arithmetic element42 that is a NOR circuit having a high logical threshold value andgenerates a pulse signal (VCO PULSE). Then, as the feedback signal (PFB)for accelerating signal transition in the second stage of the comparisoncircuit 22, a delay signal inverted by the inversion element 43 that isan inverter is used.

FIG. 11 is a circuit diagram depicting a configuration example of thepulse generation circuit of FIG. 6 in the case where a NAND circuit isused as the arithmetic element.

The pulse generation circuit 25 of FIG. 11 uses an arithmetic element 42that is a NAND circuit and generates a pulse signal (VCO XPULSE) of anopposite phase to that of the pulse generation circuit 25 of FIG. 6. Inparticular, the pulse generation circuit 25 of FIG. 11 receives theinverted output (VCO) of the comparison circuit 22 as an input signalthereto and generates a delay signal using a delay element 41-1 andanother delay element 41-2 that are inverters having low logic.

Further, in the pulse generation circuit 25, the delay signal and asignal obtained by inverting the inverted output of the comparisoncircuit 22 by the inversion element 43 are inputted to the arithmeticelement 42 that is a NAND circuit, so that a pulse signal (VCO PULSE) isgenerated. Then, as the feedback signal (PFB) for accelerating signaltransition in the second stage of the comparison circuit 22, a delaysignal delayed by the delay element 41-1 and the delay element 41-2 isused. In particular, in the example of FIG. 11, the delay elements 41-1and 41-2 and the inversion element 43 includes an inverter, and thearithmetic element 42 includes a NAND circuit. It is to be noted that itis necessary for the logical threshold value of the inversion element 43to become higher than that of the delay element 41-1. This provides aneffect that a time width of the pulse signal is further increased. It isto be noted that, at this time, the delay element 41-2 preferably has ahigh logical threshold value.

FIG. 12 is a circuit diagram depicting a configuration example of thepulse generation circuit of FIG. 9 in the case where a NAND circuit isused as the arithmetic element.

In particular, in the pulse generation circuit 25 of FIG. 12, theelement number of transistors configuring the pulse generation circuit25 of FIG. 11 is changed to adjust the logical threshold value of thetransistors. In particular, the pulse generation circuit 25 of FIG. 12receives the inverted output (VCO) of the comparison circuit 22 as aninput thereto and generates a delay signal using the delay element 41-1that is an inverter having a low logical threshold value and the delayelement 41-2 that is an inverter having a high logical threshold value.

Further, the delay signal and a signal obtained by inverting theinverted output of the comparison circuit 22 by the inversion element 43are inputted to the arithmetic element 42 that is a NAND circuit, sothat a pulse signal (VCO PULSE) is generated. Then, as the feedbacksignal (PFB) for accelerating signal transition in the second stage ofthe comparison circuit 22, a delay signal delayed by the delay element41-1 and the delay element 41-2 is used.

FIG. 13 is a circuit diagram depicting a configuration example of thepulse generation circuit of FIG. 10 in the case where a NAND circuit isused as the arithmetic element.

In particular, in the pulse generation circuit 25 of FIG. 13, theelements of transistors configuring the pulse generation circuit 25 ofFIG. 13 are changed to those of different threshold values (HVT: HighVth Tr. and LVT: Low Vth Tr.) of the pulse generation circuit 25 of FIG.11 to adjust the logical threshold value of the transistors. Inparticular, the pulse generation circuit 25 of FIG. 13 receives theinverted output (VCO) of the comparison circuit 22 as an input signalthereto and generates a delay signal using the delay element 41-1 thatis an inverter having a low logical threshold value and the delayelement 41-2 that is an inverter having a high logical threshold value.

Further, in the pulse generation circuit 25, the delay signal and asignal obtained by inverting the inverted output of the comparisoncircuit 22 by the inversion element 43 are inputted to the arithmeticelement 42 that is a NAND circuit, so that a pulse signal (VCO PULSE) isgenerated. Then, as the feedback signal (PFB) for accelerating signaltransition in the second stage of the comparison circuit 22, a delaysignal delayed by the delay element 41-1 and the delay element 41-2 isused.

FIG. 14 is a circuit diagram depicting a configuration example of thepulse generation circuit of FIG. 6 in the case where a selector circuitis inserted.

In the pulse generation circuit 25 of FIG. 14, a selector circuit 85 isinserted in the following stage of the arithmetic element 42 to make itpossible to use a SEL signal to select a case in which the data-throughperiod of the latch circuit 26 is controlled and in another case inwhich an output of the comparison circuit 22 is used directly.

By such a configuration as just described, it is possible to deal with acase in which the time width of a pulse signal cannot be secured.

FIG. 15 is a block diagram depicting a configuration example of an ADconversion device to which the present technology is applied.

The CIS of the pixel AD method has such premises that the arearestriction is severe, that an AD conversion device is disposed for eachpixel, and that a circuit of a small area is preferable.

In the AD conversion device 61 of FIG. 15, for the object ofimplementing a small area circuit, a PFB 24 that is a speeding upcircuit is adopted in the comparator 40 in order to accelerate signaltransition in the comparison circuit 22 (comparator 40). The PFB 24requires a feedback signal. Although a comparison signal has been usedas the feedback signal in the past, in the present technology, a delaysignal is used as the feedback signal. By this, the acceleration timingof signal transition is delayed. Accordingly, a period within which thesignal transition is comparatively gentle is provided. In the pulsegeneration circuit 25 for controlling the data-through period of thelatch circuit 26, by the provision of the delay element 41 within thisperiod, a delay signal is generated at the high and low levels of thelogical threshold value. Then, a pulse signal is generated through thearithmetic element 42 from the delay signal and the comparison signal.Effects expected from this are such as described below.

1. The time width of a pulse signal can be secured sufficiently.

2. The pulse generation circuit can be formed with a small area.

3. Reduction in power consumption can be anticipated by data-throughperiod control.

FIG. 16 is a view depicting a configuration example of a solid-stateimaging element of the pixel AD type.

In the solid-state imaging element 1 of FIG. 16, a pixel region 3 ismounted on an upper chip 101, and an AD conversion device 61 and a logiccircuit 111 are mounted on a lower chip 102, and the upper chip 101 andthe lower chip 102 are stacked using a Cu—Cu joining technology or thelike. Since one AD conversion device 61 corresponds to one pixel, acontact between the upper and lower chips is provided for each pixel. Itis to be noted that the number of stacked layers is not limited to twolayers and may be any number as long as it is equal to or greater than2.

2. Example of Use of Image Sensor

FIG. 17 is a view depicting an example of use in which the solid-stateimaging element described above is used.

The solid-state imaging element (image sensor) described above can beused in various cases in which light such as visible light, infraredlight, ultraviolet light, or an X ray is sensed, for example, in thefollowing manner.

-   -   An apparatus for imaging an image to be provided for        appreciation such as a digital camera or portable equipment with        a camera function    -   An apparatus used for traffic such as a vehicle-carried sensor        for imaging forwardly or rearwardly, around or within an        automobile for the object of safe driving such as automatic        stopping or recognition of a state of the driver, a surveillance        camera for monitoring a traveling vehicle or a road, a distance        measurement sensor for measuring the distance between vehicles        or the like    -   An apparatus used in household appliances such as a TV set, a        refrigerator or an air conditioner for imaging a gesture of a        user and performing an apparatus operation in accordance with        the gesture    -   An apparatus for medical use or healthcare use such as an        endoscope or a device for imaging a blood vessel by reception of        infrared light    -   An apparatus for security use such as a surveillance camera for        a security application or a camera for a personal authentication        application    -   An apparatus for cosmetic use such as a skin measuring        instrument for imaging the skin or a microscope for imaging the        scalp    -   An apparatus for sports use such as an action camera or a        wearable camera for a sports application or the like    -   An apparatus for agricultural use such as a camera for        monitoring the state of fields and crops

3. Example of Electronic Equipment

<Configuration Example of Electronic Equipment>

Further, the present technology is not restricted to application to asolid-state imaging element but can be applied also to an imagingapparatus. Here, the imaging apparatus signifies electronic equipmenthaving an imaging function such as a camera system of a digital stillcamera or a digital video camera or a mobile phone. It is to be notedthat the imaging apparatus may be in the form of a module incorporatedin electronic equipment, namely, a camera module.

Here, a configuration example of electronic equipment of the presenttechnology is described with reference to FIG. 18.

The electronic equipment 300 depicted in FIG. 18 includes a solid-stateimaging element (device chip) 301, an optical lens 302, a shutter device303, a driving circuit 304, and a signal processing circuit 305. As thesolid-state imaging element 301, the solid-state imaging element 1 ofthe present technology described hereinabove is provided.

The optical lens 302 forms an image of image light (incident light) froman imaging object on an imaging plane of the solid-state imaging element301. Consequently, signal charge is accumulated for a fixed period intothe solid-state imaging element 301. The shutter device 303 controls alight irradiation period and a light blocking period for the solid-stateimaging element 301.

The driving circuit 304 supplies driving signals for controlling asignal transfer operation of the solid-state imaging element 301, ashutter operation of the shutter device 303, and a light emissionoperation of a light emitting section not depicted. The driving circuit304 controls various operations using parameters set by a CPU notdepicted. The solid-state imaging element 301 performs signal transferin response to a driving signal (timing signal) supplied from thedriving circuit 304. The signal processing circuit 305 performs varioussignal processes for a signal outputted from the solid-state imagingelement 301. An image signal for which the signal processes have beenperformed is stored into a storage medium such as a memory or outputtedto a monitor.

4. Application Example to In-Vivo Information Acquisition System

The technology according to the present disclosure (present technology)can be applied to various products. For example, the technologyaccording to the present disclosure may be applied to an endoscopicsurgery system.

FIG. 19 is a block diagram depicting an example of a schematicconfiguration of an in-vivo information acquisition system of a patientusing a capsule type endoscope, to which the technology according to anembodiment of the present disclosure (present technology) can beapplied.

The in-vivo information acquisition system 10001 includes a capsule typeendoscope 10100 and an external controlling apparatus 10200.

The capsule type endoscope 10100 is swallowed by a patient at the timeof inspection. The capsule type endoscope 10100 has an image pickupfunction and a wireless communication function and successively picks upan image of the inside of an organ such as the stomach or an intestine(hereinafter referred to as in-vivo image) at predetermined intervalswhile it moves inside of the organ by peristaltic motion for a period oftime until it is naturally discharged from the patient. Then, thecapsule type endoscope 10100 successively transmits information of thein-vivo image to the external controlling apparatus 10200 outside thebody by wireless transmission.

The external controlling apparatus 10200 integrally controls operationof the in-vivo information acquisition system 10001. Further, theexternal controlling apparatus 10200 receives information of an in-vivoimage transmitted thereto from the capsule type endoscope 10100 andgenerates image data for displaying the in-vivo image on a displayapparatus (not depicted) on the basis of the received information of thein-vivo image.

In the in-vivo information acquisition system 10001, an in-vivo imageimaged a state of the inside of the body of a patient can be acquired atany time in this manner for a period of time until the capsule typeendoscope 10100 is discharged after it is swallowed.

A configuration and functions of the capsule type endoscope 10100 andthe external controlling apparatus 10200 are described in more detailbelow.

The capsule type endoscope 10100 includes a housing 10101 of the capsuletype, in which a light source unit 10111, an image pickup unit 10112, animage processing unit 10113, a wireless communication unit 10114, apower feeding unit 10115, a power supply unit 10116 and a control unit10117 are accommodated.

The light source unit 10111 includes a light source such as, forexample, a light emitting diode (LED) and irradiates light on an imagepickup field-of-view of the image pickup unit 10112.

The image pickup unit 10112 includes an image pickup element and anoptical system including a plurality of lenses provided at a precedingstage to the image pickup element. Reflected light (hereinafter referredto as observation light) of light irradiated on a body tissue which isan observation target is condensed by the optical system and introducedinto the image pickup element. In the image pickup unit 10112, theincident observation light is photoelectrically converted by the imagepickup element, by which an image signal corresponding to theobservation light is generated. The image signal generated by the imagepickup unit 10112 is provided to the image processing unit 10113.

The image processing unit 10113 includes a processor such as a centralprocessing unit (CPU) or a graphics processing unit (GPU) and performsvarious signal processes for an image signal generated by the imagepickup unit 10112. The image processing unit 10113 provides the imagesignal for which the signal processes have been performed thereby as RAWdata to the wireless communication unit 10114.

The wireless communication unit 10114 performs a predetermined processsuch as a modulation process for the image signal for which the signalprocesses have been performed by the image processing unit 10113 andtransmits the resulting image signal to the external controllingapparatus 10200 through an antenna 10114A. Further, the wirelesscommunication unit 10114 receives a control signal relating to drivingcontrol of the capsule type endoscope 10100 from the externalcontrolling apparatus 10200 through the antenna 10114A. The wirelesscommunication unit 10114 provides the control signal received from theexternal controlling apparatus 10200 to the control unit 10117.

The power feeding unit 10115 includes an antenna coil for powerreception, a power regeneration circuit for regenerating electric powerfrom current generated in the antenna coil, a voltage booster circuitand so forth. The power feeding unit 10115 generates electric powerusing the principle of non-contact charging.

The power supply unit 10116 includes a secondary battery and storeselectric power generated by the power feeding unit 10115. In FIG. 19, inorder to avoid complicated illustration, an arrow mark indicative of asupply destination of electric power from the power supply unit 10116and so forth are omitted. However, electric power stored in the powersupply unit 10116 is supplied to and can be used to drive the lightsource unit 10111, the image pickup unit 10112, the image processingunit 10113, the wireless communication unit 10114 and the control unit10117.

The control unit 10117 includes a processor such as a CPU and suitablycontrols driving of the light source unit 10111, the image pickup unit10112, the image processing unit 10113, the wireless communication unit10114 and the power feeding unit 10115 in accordance with a controlsignal transmitted thereto from the external controlling apparatus10200.

The external controlling apparatus 10200 includes a processor such as aCPU or a GPU, a microcomputer, a control board or the like in which aprocessor and a storage element such as a memory are mixedlyincorporated. The external controlling apparatus 10200 transmits acontrol signal to the control unit 10117 of the capsule type endoscope10100 through an antenna 10200A to control operation of the capsule typeendoscope 10100. In the capsule type endoscope 10100, an irradiationcondition of light upon an observation target of the light source unit10111 can be changed, for example, in accordance with a control signalfrom the external controlling apparatus 10200. Further, an image pickupcondition (for example, a frame rate, an exposure value or the like ofthe image pickup unit 10112) can be changed in accordance with a controlsignal from the external controlling apparatus 10200. Further, thesubstance of processing by the image processing unit 10113 or acondition for transmitting an image signal from the wirelesscommunication unit 10114 (for example, a transmission interval, atransmission image number or the like) may be changed in accordance witha control signal from the external controlling apparatus 10200.

Further, the external controlling apparatus 10200 performs various imageprocesses for an image signal transmitted thereto from the capsule typeendoscope 10100 to generate image data for displaying a picked upin-vivo image on the display apparatus. As the image processes, varioussignal processes can be performed such as, for example, a developmentprocess (demosaic process), an image quality improving process(bandwidth enhancement process, a super-resolution process, a noisereduction (NR) process and/or image stabilization process) and/or anenlargement process (electronic zooming process). The externalcontrolling apparatus 10200 controls driving of the display apparatus tocause the display apparatus to display a picked up in-vivo image on thebasis of generated image data. Alternatively, the external controllingapparatus 10200 may also control a recording apparatus (not depicted) torecord generated image data or control a printing apparatus (notdepicted) to output generated image data by printing.

An example of an in-vivo information acquisition system to which thetechnology according to the present disclosure can be applied has beendescribed. The technology according to the present disclosure can beapplied to the image pickup unit 10112 from within the configurationdescribed hereinabove. In particular, for example, the solid-stateimaging element 1 of FIG. 16 can be applied to the image pickup unit10112. By applying the technology according to the present disclosure tothe image pickup unit 10112, the time width of a pulse signal can besecured sufficiently, and the pixel size can be reduced. Accordingly, itis possible to downsize the apparatus, for example. Further, reductionin power consumption can be anticipated.

5. Application Example to Endoscopic Surgery System

The technology according to the present disclosure (present technology)can be applied to various products. For example, the technologyaccording to the present disclosure may be applied to an endoscopicsurgery system.

FIG. 20 is a view depicting an example of a schematic configuration ofan endoscopic surgery system to which the technology according to anembodiment of the present disclosure (present technology) can beapplied.

In FIG. 20, a state is illustrated in which a surgeon (medical doctor)11131 is using an endoscopic surgery system 11000 to perform surgery fora patient 11132 on a patient bed 11133. As depicted, the endoscopicsurgery system 11000 includes an endoscope 11100, other surgical tools11110 such as a pneumoperitoneum tube 11111 and an energy device 11112,a supporting arm apparatus 11120 which supports the endoscope 11100thereon, and a cart 11200 on which various apparatus for endoscopicsurgery are mounted.

The endoscope 11100 includes a lens barrel 11101 having a region of apredetermined length from a distal end thereof to be inserted into abody cavity of the patient 11132, and a camera head 11102 connected to aproximal end of the lens barrel 11101. In the example depicted, theendoscope 11100 is depicted which includes as a rigid endoscope havingthe lens barrel 11101 of the hard type. However, the endoscope 11100 mayotherwise be included as a flexible endoscope having the lens barrel11101 of the flexible type.

The lens barrel 11101 has, at a distal end thereof, an opening in whichan objective lens is fitted. A light source apparatus 11203 is connectedto the endoscope 11100 such that light generated by the light sourceapparatus 11203 is introduced to a distal end of the lens barrel 11101by a light guide extending in the inside of the lens barrel 11101 and isirradiated toward an observation target in a body cavity of the patient11132 through the objective lens. It is to be noted that the endoscope11100 may be a forward-viewing endoscope or may be an oblique-viewingendoscope or a side-viewing endoscope.

An optical system and an image pickup element are provided in the insideof the camera head 11102 such that reflected light (observation light)from the observation target is condensed on the image pickup element bythe optical system. The observation light is photo-electricallyconverted by the image pickup element to generate an electric signalcorresponding to the observation light, namely, an image signalcorresponding to an observation image. The image signal is transmittedas RAW data to a CCU 11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU) or the like and integrally controls operation ofthe endoscope 11100 and a display apparatus 11202. Further, the CCU11201 receives an image signal from the camera head 11102 and performs,for the image signal, various image processes for displaying an imagebased on the image signal such as, for example, a development process(demosaic process).

The display apparatus 11202 displays thereon an image based on an imagesignal, for which the image processes have been performed by the CCU11201, under the control of the CCU 11201.

The light source apparatus 11203 includes a light source such as, forexample, a light emitting diode (LED) and supplies irradiation lightupon imaging of a surgical region to the endoscope 11100.

An inputting apparatus 11204 is an input interface for the endoscopicsurgery system 11000. A user can perform inputting of various kinds ofinformation or instruction inputting to the endoscopic surgery system11000 through the inputting apparatus 11204. For example, the user wouldinput an instruction or a like to change an image pickup condition (typeof irradiation light, magnification, focal distance or the like) by theendoscope 11100.

A treatment tool controlling apparatus 11205 controls driving of theenergy device 11112 for cautery or incision of a tissue, sealing of ablood vessel or the like. A pneumoperitoneum apparatus 11206 feeds gasinto a body cavity of the patient 11132 through the pneumoperitoneumtube 11111 to inflate the body cavity in order to secure the field ofview of the endoscope 11100 and secure the working space for thesurgeon. A recorder 11207 is an apparatus capable of recording variouskinds of information relating to surgery. A printer 11208 is anapparatus capable of printing various kinds of information relating tosurgery in various forms such as a text, an image or a graph.

It is to be noted that the light source apparatus 11203 which suppliesirradiation light when a surgical region is to be imaged to theendoscope 11100 may include a white light source which includes, forexample, an LED, a laser light source or a combination of them. Where awhite light source includes a combination of red, green, and blue (RGB)laser light sources, since the output intensity and the output timingcan be controlled with a high degree of accuracy for each color (eachwavelength), adjustment of the white balance of a picked up image can beperformed by the light source apparatus 11203. Further, in this case, iflaser beams from the respective RGB laser light sources are irradiatedtime-divisionally on an observation target and driving of the imagepickup elements of the camera head 11102 are controlled in synchronismwith the irradiation timings. Then images individually corresponding tothe R, G and B colors can be also picked up time-divisionally. Accordingto this method, a color image can be obtained even if color filters arenot provided for the image pickup element.

Further, the light source apparatus 11203 may be controlled such thatthe intensity of light to be outputted is changed for each predeterminedtime. By controlling driving of the image pickup element of the camerahead 11102 in synchronism with the timing of the change of the intensityof light to acquire images time-divisionally and synthesizing theimages, an image of a high dynamic range free from underexposed blockedup shadows and overexposed highlights can be created.

Further, the light source apparatus 11203 may be configured to supplylight of a predetermined wavelength band ready for special lightobservation. In special light observation, for example, by utilizing thewavelength dependency of absorption of light in a body tissue toirradiate light of a narrow band in comparison with irradiation lightupon ordinary observation (namely, white light), narrow band observation(narrow band imaging) of imaging a predetermined tissue such as a bloodvessel of a superficial portion of the mucous membrane or the like in ahigh contrast is performed. Alternatively, in special light observation,fluorescent observation for obtaining an image from fluorescent lightgenerated by irradiation of excitation light may be performed. Influorescent observation, it is possible to perform observation offluorescent light from a body tissue by irradiating excitation light onthe body tissue (autofluorescence observation) or to obtain afluorescent light image by locally injecting a reagent such asindocyanine green (ICG) into a body tissue and irradiating excitationlight corresponding to a fluorescent light wavelength of the reagentupon the body tissue. The light source apparatus 11203 can be configuredto supply such narrow-band light and/or excitation light suitable forspecial light observation as described above.

FIG. 21 is a block diagram depicting an example of a functionalconfiguration of the camera head 11102 and the CCU 11201 depicted inFIG. 20.

The camera head 11102 includes a lens unit 11401, an image pickup unit11402, a driving unit 11403, a communication unit 11404 and a camerahead controlling unit 11405. The CCU 11201 includes a communication unit11411, an image processing unit 11412 and a control unit 11413. Thecamera head 11102 and the CCU 11201 are connected for communication toeach other by a transmission cable 11400.

The lens unit 11401 is an optical system, provided at a connectinglocation to the lens barrel 11101. Observation light taken in from adistal end of the lens barrel 11101 is guided to the camera head 11102and introduced into the lens unit 11401. The lens unit 11401 includes acombination of a plurality of lenses including a zoom lens and afocusing lens.

The number of image pickup elements which is included by the imagepickup unit 11402 may be one (single-plate type) or a plural number(multi-plate type). Where the image pickup unit 11402 is configured asthat of the multi-plate type, for example, image signals correspondingto respective R, G and B are generated by the image pickup elements, andthe image signals may be synthesized to obtain a color image. The imagepickup unit 11402 may also be configured so as to have a pair of imagepickup elements for acquiring respective image signals for the right eyeand the left eye ready for three dimensional (3D) display. If 3D displayis performed, then the depth of a living body tissue in a surgicalregion can be comprehended more accurately by the surgeon 11131. It isto be noted that, where the image pickup unit 11402 is configured asthat of stereoscopic type, a plurality of systems of lens units 11401are provided corresponding to the individual image pickup elements.

Further, the image pickup unit 11402 may not necessarily be provided onthe camera head 11102. For example, the image pickup unit 11402 may beprovided immediately behind the objective lens in the inside of the lensbarrel 11101.

The driving unit 11403 includes an actuator and moves the zoom lens andthe focusing lens of the lens unit 11401 by a predetermined distancealong an optical axis under the control of the camera head controllingunit 11405. Consequently, the magnification and the focal point of apicked up image by the image pickup unit 11402 can be adjusted suitably.

The communication unit 11404 includes a communication apparatus fortransmitting and receiving various kinds of information to and from theCCU 11201. The communication unit 11404 transmits an image signalacquired from the image pickup unit 11402 as RAW data to the CCU 11201through the transmission cable 11400.

In addition, the communication unit 11404 receives a control signal forcontrolling driving of the camera head 11102 from the CCU 11201 andsupplies the control signal to the camera head controlling unit 11405.The control signal includes information relating to image pickupconditions such as, for example, information that a frame rate of apicked up image is designated, information that an exposure value uponimage picking up is designated and/or information that a magnificationand a focal point of a picked up image are designated.

It is to be noted that the image pickup conditions such as the framerate, exposure value, magnification or focal point may be designated bythe user or may be set automatically by the control unit 11413 of theCCU 11201 on the basis of an acquired image signal. In the latter case,an auto exposure (AE) function, an auto focus (AF) function and an autowhite balance (AWB) function are incorporated in the endoscope 11100.

The camera head controlling unit 11405 controls driving of the camerahead 11102 on the basis of a control signal from the CCU 11201 receivedthrough the communication unit 11404.

The communication unit 11411 includes a communication apparatus fortransmitting and receiving various kinds of information to and from thecamera head 11102. The communication unit 11411 receives an image signaltransmitted thereto from the camera head 11102 through the transmissioncable 11400.

Further, the communication unit 11411 transmits a control signal forcontrolling driving of the camera head 11102 to the camera head 11102.The image signal and the control signal can be transmitted by electricalcommunication, optical communication or the like.

The image processing unit 11412 performs various image processes for animage signal in the form of RAW data transmitted thereto from the camerahead 11102.

The control unit 11413 performs various kinds of control relating toimage picking up of a surgical region or the like by the endoscope 11100and display of a picked up image obtained by image picking up of thesurgical region or the like. For example, the control unit 11413 createsa control signal for controlling driving of the camera head 11102.

Further, the control unit 11413 controls, on the basis of an imagesignal for which image processes have been performed by the imageprocessing unit 11412, the display apparatus 11202 to display a pickedup image in which the surgical region or the like is imaged. Thereupon,the control unit 11413 may recognize various objects in the picked upimage using various image recognition technologies. For example, thecontrol unit 11413 can recognize a surgical tool such as forceps, aparticular living body region, bleeding, mist when the energy device11112 is used and so forth by detecting the shape, color and so forth ofedges of objects included in a picked up image. The control unit 11413may cause, when it controls the display apparatus 11202 to display apicked up image, various kinds of surgery supporting information to bedisplayed in an overlapping manner with an image of the surgical regionusing a result of the recognition. Where surgery supporting informationis displayed in an overlapping manner and presented to the surgeon11131, the burden on the surgeon 11131 can be reduced and the surgeon11131 can proceed with the surgery with certainty.

The transmission cable 11400 which connects the camera head 11102 andthe CCU 11201 to each other is an electric signal cable ready forcommunication of an electric signal, an optical fiber ready for opticalcommunication or a composite cable ready for both of electrical andoptical communications.

Here, while, in the example depicted, communication is performed bywired communication using the transmission cable 11400, thecommunication between the camera head 11102 and the CCU 11201 may beperformed by wireless communication.

An example of an endoscopic surgery system to which the technologyaccording to the present disclosure can be applied has been described.The technology according to the present disclosure can be applied to theendoscope 11100 or the (image pickup unit 11402 of the) camera head11102 from within the configuration described hereinabove. For example,the solid-state imaging element 1 of FIG. 16 can be applied to theendoscope 11100 or (the image pickup unit 11402 of) the camera head11102. By applying the technology according to the present disclosure tothe endoscope 11100 or (the image pickup unit 11402 of) the camera head11102, it is possible to sufficiently secure a time width of a pulsesignal and reduce a pixel size, and therefore, for example, theapparatus can be downsized. Further, it is possible to achieve reductionof power consumption.

It is to be noted that, while an endoscopic surgery system is describedhere as an example, the technology according to the present disclosurecan be applied, for example, to a microsurgery system.

6. Application Example to Moving Body

The technology according to the present disclosure (present technology)can be applied to various products. For example, the technologyaccording to the present disclosure may be implemented as an apparatusthat is incorporated in any type of moving body such as an automobile,an electric car, a hybrid electric car, a motorcycle, a bicycle, apersonal mobility, an airplane, a drone, a ship, or a robot.

FIG. 22 is a block diagram depicting an example of schematicconfiguration of a vehicle control system as an example of a mobile bodycontrol system to which the technology according to an embodiment of thepresent disclosure can be applied.

The vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example depicted in FIG. 22, the vehicle control system 12000includes a driving system control unit 12010, a body system control unit12020, an outside-vehicle information detecting unit 12030, anin-vehicle information detecting unit 12040, and an integrated controlunit 12050. In addition, a microcomputer 12051, a sound/image outputsection 12052, and a vehicle-mounted network interface (I/F) 12053 areillustrated as a functional configuration of the integrated control unit12050.

The driving system control unit 12010 controls the operation of devicesrelated to the driving system of the vehicle in accordance with variouskinds of programs. For example, the driving system control unit 12010functions as a control device for a driving force generating device forgenerating the driving force of the vehicle, such as an internalcombustion engine, a driving motor, or the like, a driving forcetransmitting mechanism for transmitting the driving force to wheels, asteering mechanism for adjusting the steering angle of the vehicle, abraking device for generating the braking force of the vehicle, and thelike.

The body system control unit 12020 controls the operation of variouskinds of devices provided to a vehicle body in accordance with variouskinds of programs. For example, the body system control unit 12020functions as a control device for a keyless entry system, a smart keysystem, a power window device, or various kinds of lamps such as aheadlamp, a backup lamp, a brake lamp, a turn signal, a fog lamp, or thelike. In this case, radio waves transmitted from a mobile device as analternative to a key or signals of various kinds of switches can beinput to the body system control unit 12020. The body system controlunit 12020 receives these input radio waves or signals, and controls adoor lock device, the power window device, the lamps, or the like of thevehicle.

The outside-vehicle information detecting unit 12030 detects informationabout the outside of the vehicle including the vehicle control system12000. For example, the outside-vehicle information detecting unit 12030is connected with an imaging section 12031. The outside-vehicleinformation detecting unit 12030 makes the imaging section 12031 imagean image of the outside of the vehicle, and receives the imaged image.On the basis of the received image, the outside-vehicle informationdetecting unit 12030 may perform processing of detecting an object suchas a human, a vehicle, an obstacle, a sign, a character on a roadsurface, or the like, or processing of detecting a distance thereto.

The imaging section 12031 is an optical sensor that receives light, andwhich outputs an electric signal corresponding to a received lightamount of the light. The imaging section 12031 can output the electricsignal as an image, or can output the electric signal as informationabout a measured distance. In addition, the light received by theimaging section 12031 may be visible light, or may be invisible lightsuch as infrared rays or the like.

The in-vehicle information detecting unit 12040 detects informationabout the inside of the vehicle. The in-vehicle information detectingunit 12040 is, for example, connected with a driver state detectingsection 12041 that detects the state of a driver. The driver statedetecting section 12041, for example, includes a camera that images thedriver. On the basis of detection information input from the driverstate detecting section 12041, the in-vehicle information detecting unit12040 may calculate a degree of fatigue of the driver or a degree ofconcentration of the driver, or may determine whether the driver isdozing.

The microcomputer 12051 can calculate a control target value for thedriving force generating device, the steering mechanism, or the brakingdevice on the basis of the information about the inside or outside ofthe vehicle which information is obtained by the outside-vehicleinformation detecting unit 12030 or the in-vehicle information detectingunit 12040, and output a control command to the driving system controlunit 12010. For example, the microcomputer 12051 can perform cooperativecontrol intended to implement functions of an advanced driver assistancesystem (ADAS) which functions include collision avoidance or shockmitigation for the vehicle, following driving based on a followingdistance, vehicle speed maintaining driving, a warning of collision ofthe vehicle, a warning of deviation of the vehicle from a lane, or thelike.

In addition, the microcomputer 12051 can perform cooperative controlintended for automatic driving, which makes the vehicle to travelautonomously without depending on the operation of the driver, or thelike, by controlling the driving force generating device, the steeringmechanism, the braking device, or the like on the basis of theinformation about the outside or inside of the vehicle which informationis obtained by the outside-vehicle information detecting unit 12030 orthe in-vehicle information detecting unit 12040.

In addition, the microcomputer 12051 can output a control command to thebody system control unit 12020 on the basis of the information about theoutside of the vehicle which information is obtained by theoutside-vehicle information detecting unit 12030. For example, themicrocomputer 12051 can perform cooperative control intended to preventa glare by controlling the headlamp so as to change from a high beam toa low beam, for example, in accordance with the position of a precedingvehicle or an oncoming vehicle detected by the outside-vehicleinformation detecting unit 12030.

The sound/image output section 12052 transmits an output signal of atleast one of a sound and an image to an output device capable ofvisually or auditorily notifying information to an occupant of thevehicle or the outside of the vehicle. In the example of FIG. 22, anaudio speaker 12061, a display section 12062, and an instrument panel12063 are illustrated as the output device. The display section 12062may, for example, include at least one of an on-board display and ahead-up display.

FIG. 23 is a diagram depicting an example of the installation positionof the imaging section 12031.

In FIG. 23, the imaging section 12031 includes imaging sections 12101,12102, 12103, 12104, and 12105.

The imaging sections 12101, 12102, 12103, 12104, and 12105 are, forexample, disposed at positions on a front nose, sideview mirrors, a rearbumper, and a back door of the vehicle 12100 as well as a position on anupper portion of a windshield within the interior of the vehicle. Theimaging section 12101 provided to the front nose and the imaging section12105 provided to the upper portion of the windshield within theinterior of the vehicle obtain mainly an image of the front of thevehicle 12100. The imaging sections 12102 and 12103 provided to thesideview mirrors obtain mainly an image of the sides of the vehicle12100. The imaging section 12104 provided to the rear bumper or the backdoor obtains mainly an image of the rear of the vehicle 12100. Theimaging section 12105 provided to the upper portion of the windshieldwithin the interior of the vehicle is used mainly to detect a precedingvehicle, a pedestrian, an obstacle, a signal, a traffic sign, a lane, orthe like.

Incidentally, FIG. 23 depicts an example of photographing ranges of theimaging sections 12101 to 12104. An imaging range 12111 represents theimaging range of the imaging section 12101 provided to the front nose.Imaging ranges 12112 and 12113 respectively represent the imaging rangesof the imaging sections 12102 and 12103 provided to the sideviewmirrors. An imaging range 12114 represents the imaging range of theimaging section 12104 provided to the rear bumper or the back door. Abird's-eye image of the vehicle 12100 as viewed from above is obtainedby superimposing image data imaged by the imaging sections 12101 to12104, for example.

At least one of the imaging sections 12101 to 12104 may have a functionof obtaining distance information. For example, at least one of theimaging sections 12101 to 12104 may be a stereo camera constituted of aplurality of imaging elements, or may be an imaging element havingpixels for phase difference detection.

For example, the microcomputer 12051 can determine a distance to eachthree-dimensional object within the imaging ranges 12111 to 12114 and atemporal change in the distance (relative speed with respect to thevehicle 12100) on the basis of the distance information obtained fromthe imaging sections 12101 to 12104, and thereby extract, as a precedingvehicle, a nearest three-dimensional object in particular that ispresent on a traveling path of the vehicle 12100 and which travels insubstantially the same direction as the vehicle 12100 at a predeterminedspeed (for example, equal to or more than 0 km/hour). Further, themicrocomputer 12051 can set a following distance to be maintained infront of a preceding vehicle in advance, and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), or the like. It is thuspossible to perform cooperative control intended for automatic drivingthat makes the vehicle travel autonomously without depending on theoperation of the driver or the like.

For example, the microcomputer 12051 can classify three-dimensionalobject data on three-dimensional objects into three-dimensional objectdata of a two-wheeled vehicle, a standard-sized vehicle, a large-sizedvehicle, a pedestrian, a utility pole, and other three-dimensionalobjects on the basis of the distance information obtained from theimaging sections 12101 to 12104, extract the classifiedthree-dimensional object data, and use the extracted three-dimensionalobject data for automatic avoidance of an obstacle. For example, themicrocomputer 12051 identifies obstacles around the vehicle 12100 asobstacles that the driver of the vehicle 12100 can recognize visuallyand obstacles that are difficult for the driver of the vehicle 12100 torecognize visually. Then, the microcomputer 12051 determines a collisionrisk indicating a risk of collision with each obstacle. In a situationin which the collision risk is equal to or higher than a set value andthere is thus a possibility of collision, the microcomputer 12051outputs a warning to the driver via the audio speaker 12061 or thedisplay section 12062, and performs forced deceleration or avoidancesteering via the driving system control unit 12010. The microcomputer12051 can thereby assist in driving to avoid collision.

At least one of the imaging sections 12101 to 12104 may be an infraredcamera that detects infrared rays. The microcomputer 12051 can, forexample, recognize a pedestrian by determining whether or not there is apedestrian in imaged images of the imaging sections 12101 to 12104. Suchrecognition of a pedestrian is, for example, performed by a procedure ofextracting characteristic points in the imaged images of the imagingsections 12101 to 12104 as infrared cameras and a procedure ofdetermining whether or not it is the pedestrian by performing patternmatching processing on a series of characteristic points representingthe contour of the object. When the microcomputer 12051 determines thatthere is a pedestrian in the imaged images of the imaging sections 12101to 12104, and thus recognizes the pedestrian, the sound/image outputsection 12052 controls the display section 12062 so that a squarecontour line for emphasis is displayed so as to be superimposed on therecognized pedestrian. The sound/image output section 12052 may alsocontrol the display section 12062 so that an icon or the likerepresenting the pedestrian is displayed at a desired position.

An example of a vehicle control system to which the technology accordingto the present disclosure can be applied has been described. Thetechnology according to the present disclosure can be applied, forexample, to the imaging section 12031 (including the imaging sections12101 to 12104) or the like from within the configuration describedabove. In particular, for example, the solid-state imaging element 1 ofFIG. 16 can be applied to the imaging section 12031 (including theimaging sections 12101 to 12104). By applying the technology accordingto the present disclosure to the imaging section 12031 (including theimaging sections 12101 to 12104), it is possible to sufficiently securea time width of a pulse signal and reduce a pixel size, and therefore,for example, the apparatus can be downsized. Further, it is possible toachieve reduction of power consumption.

It is to be noted that, in the present specification, the steps thatdescribe the series of processes described hereinabove not only includeprocesses that are performed in a time series in accordance with theorder described but also include processes that are executed in parallelor individually even if they are not necessarily be processed in a timeseries.

Further, the embodiment in the present disclosure is not limited to theembodiments described hereinabove and can be altered in various mannerswithout departing from the subject matter of the present disclosure.

Further, a component described as one apparatus (or processing section)in the foregoing description may be divided so as to be configured as aplurality of apparatuses (or processing sections). Conversely,components described as a plurality of apparatuses (or processingsections) in the foregoing description may be collected so as to beconfigured as a single apparatus (or processing section). Naturally, acomponent other than those described hereinabove may be added to theconfiguration of each apparatus (or each processing section).Furthermore, if a configuration or operation as an entire system issubstantially same, part of components of a certain apparatus (orprocessing section) may be included in a configuration of some otherapparatus (or some other processing section). In short, the presenttechnology is not limited to the embodiments described above and can bealtered in various manners without departing from the subject matter ofthe present technology.

Although the preferred embodiments of the present disclosure have beendescribed in detail with reference to the accompanying drawings, thedisclosure is not limited to such examples as described above. It isapparent that persons who have common knowledge in the technical fieldto which the present disclosure pertains could have conceived variousalterations or modifications within the scope of the technical ideadescribed in the claims, and it is understood that those naturally fallwithin the technical scope of the present disclosure.

It is to be noted that the present disclosure can assume such aconfiguration as described below.

(1) A solid-state imaging element, including:

a pixel array section in which unit pixels each having a photoelectricconversion section are disposed; and

an AD converter for each of the unit pixels, in which the AD converterincludes

-   -   a pulse generation circuit that feeds back a delay signal        obtained by delaying an output signal of a comparator to the        comparator and performs arithmetic operation of the output        signal and the delay signal to generate a pulse signal, and    -   a latch circuit that latches a data code using the pulse signal        generated by the pulse generation circuit.

(2) The solid-state imaging element according to (1) above, in which

the pulse generation circuit includes:

-   -   a delay element that delays the output signal of the comparator        to generate the delay signal; and    -   an arithmetic element that arithmetically operates the output        signal and the delay signal to generate the pulse signal.

(3) The solid-state imaging element according to (2) above, in which

the arithmetic element includes a NOR circuit.

(4) The solid-state imaging element according to (2) above, in which

the arithmetic element includes a NAND circuit.

(5) The solid-state imaging element according to any one of (1) to (4)above, in which in the pulse generation circuit, a logical thresholdvalue of a gate element is adjusted.

(6) The solid-state imaging element according to (5) above, in which

in the pulse generation circuit, the logical threshold value of the gateelement is adjusted by changing an element number of transistors.

(7) The solid-state imaging element according to (5) above, in which

in the pulse generation circuit, the logical threshold value of the gateelement is adjusted by setting the threshold value of the elements oftransistors to a high threshold value and a low threshold value.

(8) The solid-state imaging element according to any one of (1) to (7)above, in which

the pulse generation circuit further includes a selection circuit thatselects a path used when a delay signal obtained by delaying the outputsignal of the comparator is to be fed back to the comparator and theoutput signal and the delay signal are arithmetically operated togenerate a pulse signal and another path used when the output signal ofthe comparator is to be used as it is.

(9) The solid-state imaging element according to any one of (1) to (8)above, in which

the solid-state imaging element includes a stacked type solid-stateimaging element.

(10) Electronic equipment including:

a solid-state imaging element including

-   -   a pixel array section in which unit pixels each having a        photoelectric conversion section are disposed, and    -   an AD converter for each of the unit pixels, in which the AD        converter includes    -   a pulse generation circuit that feeds back a delay signal        obtained by delaying an output signal of a comparator to the        comparator and performs arithmetic operation of the output        signal and the delay signal to generate a pulse signal, and    -   a latch circuit that latches a data code using the pulse signal        generated by the pulse generation circuit;

a signal processing circuit that processes an output signal outputtedfrom the solid-state imaging element; and

an optical system that enters incident light into the solid-stateimaging element.

REFERENCE SIGNS LIST

1 Solid-state imaging element, 3 Pixel region, 8 Control circuit, 22Comparator, 23 Auto zero, 24 PFB, 25 Pulse generation circuit, 26 Latchcircuit, 31 Repeater, 32 RAM CDS, 33 Gray Code, 40 Comparison circuit,41, 41-1, 41-2 Delay element, 42 Arithmetic element, 43 Inversionelement, 51 AD converter, 61 AD conversion device, 71, 72 Inverter, 81Upper chip, 85 Selector circuit, 101 Upper chip, 102 Lower chip, 111Logic circuit, 300 Electronic equipment, 301 Solid-state imaging device,302 Optical lens, 303 Shutter device, 304 Driving circuit, 305 Signalprocessing circuit

The invention claimed is:
 1. A solid-state imaging element, comprising:a pixel array section in which unit pixels each having a photoelectricconversion section are disposed; and an AD converter for each of theunit pixels, wherein the AD converter includes a pulse generationcircuit that feeds back a delay signal obtained by delaying an outputsignal of a comparator to the comparator and performs arithmeticoperation of the output signal and the delay signal to generate a pulsesignal, and a latch circuit that latches a data code using the pulsesignal generated by the pulse generation circuit.
 2. The solid-stateimaging element according to claim 1, wherein the pulse generationcircuit includes: a delay element that delays the output signal of thecomparator to generate the delay signal; and an arithmetic element thatarithmetically operates the output signal and the delay signal togenerate the pulse signal.
 3. The solid-state imaging element accordingto claim 2, wherein the arithmetic element includes a NOR circuit. 4.The solid-state imaging element according to claim 2, wherein thearithmetic element includes a NAND circuit.
 5. The solid-state imagingelement according to claim 1, wherein in the pulse generation circuit, alogical threshold value of a gate element is adjusted.
 6. Thesolid-state imaging element according to claim 5, wherein in the pulsegeneration circuit, the logical threshold value of the gate element isadjusted by changing an element number of transistors.
 7. Thesolid-state imaging element according to claim 5, wherein in the pulsegeneration circuit, the logical threshold value of the gate element isadjusted by setting a threshold value of each of the elements oftransistors to a high threshold value and a low threshold value.
 8. Thesolid-state imaging element according to claim 1, wherein the pulsegeneration circuit further includes a selection circuit that selects apath used when the delay signal obtained by delaying the output signalof the comparator is to be fed back to the comparator and the outputsignal and the delay signal are arithmetically operated to generate thepulse signal and another path used when the output signal of thecomparator is to be used as it is.
 9. The solid-state imaging elementaccording to claim 1, wherein the solid-state imaging element includes astacked type solid-state imaging element.
 10. Electronic equipmentcomprising: a solid-state imaging element including a pixel arraysection in which unit pixels each having a photoelectric conversionsection are disposed, and an AD converter for each of the unit pixels,in which the AD converter includes a pulse generation circuit that feedsback a delay signal obtained by delaying an output signal of acomparator to the comparator and performs arithmetic operation of theoutput signal and the delay signal to generate a pulse signal, and alatch circuit that latches a data code using the pulse signal generatedby the pulse generation circuit; a signal processing circuit thatprocesses an output signal outputted from the solid-state imagingelement; and an optical system that enters incident light into thesolid-state imaging element.